Electric switch



Octfi 11, 192?. H. HUBER ELECTRIC SWITCH Filed Nov. 22, 1922 Inventor.Herman J. H.HubeY b9 7 f is Abbe Patented Oct. 11, 1927.

'UNITED STATES} PATENT OFFICE.

HERMAN J. H. HUBER, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL EL EC-TRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application flled"November 22, 1922. Serial No. 602,629.

My invention relates to electric switches and more particularly to animproved form of switch contact member.

In the construction of electric switches it is customary to provide mainand auxiliary contact members arranged to be connected in shunt relationwith each other when the switch is closed, the main contact members beindesigned tocarry the greater part of the load current and the auxiliarycontact members being used to take the are when the circuit is made andbroken. 7,

The main contact members are usually constructed of resilient materialfor the urpose of insuring good contact between t em and the memberswith which they cooperate.

In operation, the main contacts are subject to rapid deterioration forthe reason that they are usually in the form of laminated brushes madeof strips of copper, or an alloy of copper, which has a low elasticlimit and which loses its elasticity on account of the heating and roughusage incident to the operation of the switch. As the elasticity of thebrushes decreases it becomes increasingly diflicult to maintain goodcontact, and the o eration of the switch is adversely affected It istherefore a principal object of my invention to provide meansindependent of the elasticit of the brush for insuring good contactetween the switch brushes and their cooperating contact members and toprovide an arrangement of parts well adapted to stand rough usagewlthout deterioration of the main contact.

Other objects and advantages will become apparent as my invention isconsldered in detail.

Referring now to the accompanying drawing, there is shown in the singlefigure thereof an operating rod 1 arran ed to move the bridging contactmember 2 into and out of engagement with the primary contact brushes 3and the secondary contact t-lps 4 to close and open the circuit.

The primary contact brushes 3 are secured to stationary contact heads 5Wh10l1 are supported from the frame of theswltch (not shown but which mafor example, be similar to that shown 1n Letters Patent No. 1,349,873,to C. Christensen, dated Aug. 17, 1920) by insulated bushings 6. Aspiral spring 7 is interposed between an extension 8 0. the contact head5 and the primary brush 3 to provide efl'ective contacting engagementbetween the brush 3 and the movable bridging contact member 2. Thisspring The spring assists the laminated contact in taking the closingshock of the switch and before the laminated contact is deflected to anextent great enou h permanently to injure it the movement is stopped.The extension 8 is preferably so located with respect to the brush 3 andbridging member 2 that is caseof excessively severe shocks the movementof the bridging member is limited by the rigid extension 8. Thesecondary contact tips 4 are pivotally connected to the brackets 9 whichare in turn fastened to contact heads 5 and are forced into contactrelation with the movable bridging contact member by the action of thespring 10. Electrical contact between the secondary contact tips 4 andthe contact head 5 is maintained by the flexible conductor 11. A sto 12on the secondary contact tip 4 is adapted to engage an end wall 13 ofthe bracket 9 to limit the downward movement of the secondary contacttips 4.

When it is desired to open the circuit the operating rod 1 and bridgingmember 2 are lowered, being followed within their respective ranges oftravel by the primary contact brushes 3 and the secondary contact tips4. The above ranges of travel are'fixed so that that of the primarycontact brush is less than that of the secondary contact ti 7 4. Inconsequence thereof the circuit will be transferred to the latter memberas the bridging member 2 descends and the circuit finally broken at thesecondary contact tips. While I have disclosed my invention as embodiedin a single arrangement of parts it must not be considered as limitedthereto. Similar structures will readily occur to those skilled in theart and it is my intention to cover by'the appended claims all suchembodiments as come within the spirit and of my invention.

by Letters Patent of the United States, is 1- 1. In a switch, alaminated contact brush, a contact member adapted to be raised intoengagement therewith, resilient means for maintaining ood contactbetween said brush and sai member, and a support for said brush and saidmeans constructed and arranged to maintain said means in operativerelation with said brush and to limit the deflection of said brush bysaid contact member.

2. In a switch, a flexible contact brush, a movable bridging memberdesigned to cooperate therewith, resilient means for maintaining goodcontact between said brush and said bridging member, and a fixed supportfor said brush constructed and arranged to maintain said means inoperative relation with said brush, a portion of said support beingspaced from said brush and adapted to limit the deflection thereof whenengaged by said bridging member.

3. In a switch, a flexible contact brush, a movable contact memberdesigned to cooperate therewith, a spring for maintaining good contactbetween sald brush and said contact member, a fixed support for saidbrush, and a projection upon said support spaced from said brush, saidprojection being arranged to limit the movement of said contact memberand being recessed to afford a seat ,for said sprin In witness whereo Ihave hereunto set my hand this 21st day of November, 1922.

HERMAN J. H. HUBER;

